I've been tinkering with an updated version of my Snow Prince/Ancient Steel armor mod, and for this version I'm working on a spirit that'll appear and fight you when you pick up a piece of the armor - HOWEVER, I thought maybe it would be useful for you guys as well, as like a generic Falmer ghost for dungeons? If so, I'll post it here once the textures are finished

If you're still welcoming suggestions for it, how about some snow particles floating around? Giving him a cold blue glow texture, like this one by PeterBitt might turn out cool, too. I'm a fan of the eerie atmosphere that texture creates.

So, he's pretty much working in-game now, the only problem I'm running into is getting the frost atronach particle effect to shut off after he dies - it kind of spoils the effect of seeing him fade into a pool of ectoplasm

Sounds like a good thing to have in the Tomb of the Snow Prince. I'm not sure how much use we're gonna have for it in the near future, though. The few Falmer ruins we might include are far to the east, and in the most remote and frozen parts of the mountains. Seeing a Falmer spectre should be a unique experience, just like discovering actual remains of the Snow Elves should be. Generally we swing towards keeping the Falmer a mystery as much as we can. I wouldn't include it as a generic enemy, but perhaps as a boss fight or unique enemy found in one of these ruins.

This is looking pretty damn fantastic. While it would be unfortunate to make this a rarity during actual gameplay, I agree with roerich that the Falmer should remain as obscure as possible. It would make an encounter with this guy infinitely more meaningful and spectacular, though.